From 5ed68e83db39e1f6790a625529f10f4e1d5a8f89 Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Sat, 3 Apr 2021 21:41:49 -0300
Subject: [PATCH] shader: Remove atomic flags and use mutex + cond variable for
 pipelines

---
 .../renderer_vulkan/vk_compute_pipeline.cpp       | 15 ++++++++++-----
 .../renderer_vulkan/vk_compute_pipeline.h         |  7 ++++++-
 .../renderer_vulkan/vk_graphics_pipeline.cpp      | 14 ++++++++++----
 .../renderer_vulkan/vk_graphics_pipeline.h        |  7 ++++++-
 4 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/src/video_core/renderer_vulkan/vk_compute_pipeline.cpp b/src/video_core/renderer_vulkan/vk_compute_pipeline.cpp
index 6707842ab..0bb5b852d 100644
--- a/src/video_core/renderer_vulkan/vk_compute_pipeline.cpp
+++ b/src/video_core/renderer_vulkan/vk_compute_pipeline.cpp
@@ -55,8 +55,9 @@ ComputePipeline::ComputePipeline(const Device& device, VKDescriptorPool& descrip
             .basePipelineHandle = 0,
             .basePipelineIndex = 0,
         });
-        building_flag.test_and_set();
-        building_flag.notify_all();
+        std::lock_guard lock{build_mutex};
+        is_built = true;
+        build_condvar.notify_one();
     }};
     if (thread_worker) {
         thread_worker->QueueWork(std::move(func));
@@ -75,7 +76,8 @@ void ComputePipeline::Configure(Tegra::Engines::KeplerCompute& kepler_compute,
     size_t ssbo_index{};
     for (const auto& desc : info.storage_buffers_descriptors) {
         ASSERT(desc.count == 1);
-        buffer_cache.BindComputeStorageBuffer(ssbo_index, desc.cbuf_index, desc.cbuf_offset, desc.is_written);
+        buffer_cache.BindComputeStorageBuffer(ssbo_index, desc.cbuf_index, desc.cbuf_offset,
+                                              desc.is_written);
         ++ssbo_index;
     }
     buffer_cache.UpdateComputeBuffers();
@@ -112,9 +114,12 @@ void ComputePipeline::Configure(Tegra::Engines::KeplerCompute& kepler_compute,
     PushImageDescriptors(info, samplers.data(), image_view_ids.data(), texture_cache,
                          update_descriptor_queue, image_index);
 
-    if (!building_flag.test()) {
+    if (!is_built.load(std::memory_order::relaxed)) {
         // Wait for the pipeline to be built
-        scheduler.Record([this](vk::CommandBuffer) { building_flag.wait(false); });
+        scheduler.Record([this](vk::CommandBuffer) {
+            std::unique_lock lock{build_mutex};
+            build_condvar.wait(lock, [this] { return is_built.load(std::memory_order::relaxed); });
+        });
     }
     scheduler.Record([this](vk::CommandBuffer cmdbuf) {
         cmdbuf.BindPipeline(VK_PIPELINE_BIND_POINT_COMPUTE, *pipeline);
diff --git a/src/video_core/renderer_vulkan/vk_compute_pipeline.h b/src/video_core/renderer_vulkan/vk_compute_pipeline.h
index 02da504f7..104e6cc85 100644
--- a/src/video_core/renderer_vulkan/vk_compute_pipeline.h
+++ b/src/video_core/renderer_vulkan/vk_compute_pipeline.h
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <mutex>
+#include <condition_variable>
 #include <atomic>
 
 #include "common/common_types.h"
@@ -47,7 +49,10 @@ private:
     vk::PipelineLayout pipeline_layout;
     vk::DescriptorUpdateTemplateKHR descriptor_update_template;
     vk::Pipeline pipeline;
-    std::atomic_flag building_flag{};
+
+    std::condition_variable build_condvar;
+    std::mutex build_mutex;
+    std::atomic_bool is_built{false};
 };
 
 } // namespace Vulkan
diff --git a/src/video_core/renderer_vulkan/vk_graphics_pipeline.cpp b/src/video_core/renderer_vulkan/vk_graphics_pipeline.cpp
index e8c3a5624..67de3cb79 100644
--- a/src/video_core/renderer_vulkan/vk_graphics_pipeline.cpp
+++ b/src/video_core/renderer_vulkan/vk_graphics_pipeline.cpp
@@ -135,8 +135,10 @@ GraphicsPipeline::GraphicsPipeline(Tegra::Engines::Maxwell3D& maxwell3d_,
 
         const VkRenderPass render_pass{render_pass_cache.Get(MakeRenderPassKey(state))};
         MakePipeline(device, render_pass);
-        building_flag.test_and_set();
-        building_flag.notify_all();
+
+        std::lock_guard lock{build_mutex};
+        is_built = true;
+        build_condvar.notify_one();
     }};
     if (worker_thread) {
         worker_thread->QueueWork(std::move(func));
@@ -196,8 +198,12 @@ void GraphicsPipeline::Configure(bool is_indexed) {
     texture_cache.UpdateRenderTargets(false);
     scheduler.RequestRenderpass(texture_cache.GetFramebuffer());
 
-    if (!building_flag.test()) {
-        scheduler.Record([this](vk::CommandBuffer) { building_flag.wait(false); });
+    if (!is_built.load(std::memory_order::relaxed)) {
+        // Wait for the pipeline to be built
+        scheduler.Record([this](vk::CommandBuffer) {
+            std::unique_lock lock{build_mutex};
+            build_condvar.wait(lock, [this] { return is_built.load(std::memory_order::relaxed); });
+        });
     }
     if (scheduler.UpdateGraphicsPipeline(this)) {
         scheduler.Record([this](vk::CommandBuffer cmdbuf) {
diff --git a/src/video_core/renderer_vulkan/vk_graphics_pipeline.h b/src/video_core/renderer_vulkan/vk_graphics_pipeline.h
index 4e0583157..7d14d2378 100644
--- a/src/video_core/renderer_vulkan/vk_graphics_pipeline.h
+++ b/src/video_core/renderer_vulkan/vk_graphics_pipeline.h
@@ -6,6 +6,8 @@
 
 #include <array>
 #include <atomic>
+#include <condition_variable>
+#include <mutex>
 
 #include "common/thread_worker.h"
 #include "shader_recompiler/shader_info.h"
@@ -63,7 +65,10 @@ private:
     vk::PipelineLayout pipeline_layout;
     vk::DescriptorUpdateTemplateKHR descriptor_update_template;
     vk::Pipeline pipeline;
-    std::atomic_flag building_flag{};
+
+    std::condition_variable build_condvar;
+    std::mutex build_mutex;
+    std::atomic_bool is_built{false};
 };
 
 } // namespace Vulkan